220 40937 <7da1f33f-c2c1-482f-8fc2-c23a9767a5ec@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: mihailnajdenov@gmail.com Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Can we have beginner friendly new line and deprecate std::endl? Date: Sat, 10 Nov 2018 07:24:34 -0800 (PST) Lines: 307 Approved: news@gmane.org Message-ID: <7da1f33f-c2c1-482f-8fc2-c23a9767a5ec@isocpp.org> References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_1351_153098415.1541863474451" X-Trace: blaine.gmane.org 1541863352 30660 195.159.176.226 (10 Nov 2018 15:22:32 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 10 Nov 2018 15:22:32 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBCUJ3A7GRAPRBM7QTPPQKGQERBI5UPI@isocpp.org Sat Nov 10 16:22:28 2018 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yb1-f200.google.com ([209.85.219.200]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1gLV5e-0007sj-GA for gclcip-std-proposals@m.gmane.org; Sat, 10 Nov 2018 16:22:26 +0100 Original-Received: by mail-yb1-f200.google.com with SMTP id x12-v6sf4887608ybp.9 for ; Sat, 10 Nov 2018 07:24:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=YCQy9z1WL++EU3FhRG8VRCqlXQFctsp/YzMMr+UJ1pA=; b=fkV9A+FV5+f8i4SGU8OjpeskL4WsRVgVjquj2j+T0G+BqqWbeoV4m33ndRnhMmgRDk MHQ4A2x2Sz+mOrabyHFVhegu3SK0zFT7K5UbtCgqTY/AeI18iKExQvlAQDYTAqxFUAGE sagvOrkWWbGVClWX3ZXO7yRj5O5hgGXh+8P2mo+ZlCN7ze6/06j6oTy7VwkILgTLRGC7 nJbuXWq6BLVuDl4WR7sCljzC5VzHFQQ0p7mb84rWaMA9z+0yZA89qiCNKmQXXx3tvCcs LQNEffq+vTE4LTy78XKWFV3lkoc6MR+DtRLQPVLePHJhWQuqjCsiMY+kDVWtyVPFl6Uf 0RCw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=YCQy9z1WL++EU3FhRG8VRCqlXQFctsp/YzMMr+UJ1pA=; b=Dg4sadbahk0YEZBGDr1dk0c8qH92fUd/+t6AahnlXlaQXeR5hoKnTqb+xo4aJXtEOr 0xIXJcYcgtZR351MJELLCFd3lYCI4KxiC97e9pqvETMTr7zF83SFFPN3HSAVlvLC1b6S A66fY0x3p7SqIcQn2zFd0JjTv7PRmEF1f2Y6wmtyT1QAUwglKBe6Kn1r+BAqlb/v6IlN lktJkA9CNxJRkx9U8u64vHKQvxPKUK9K0hkBNGF/SfTbd+4tJluD1AMfAUmgVRaw/aTI nqMvjzyOarZnGHj4cK11kKQe6C75flgD3CM13I1zjdXDKRkKzb/2+MbDjvxfQYH376sF EUYw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=YCQy9z1WL++EU3FhRG8VRCqlXQFctsp/YzMMr+UJ1pA=; b=NGQ4NQz8z3Tsc2hGHCQhnhSx9w9iA7B2uO2510Nr1fY8ZfQ0Ps/vFuzIx45QUl04Jy J99eCa3lAZXL4GX6laNu3KdbFqSIezZ4e4UceKYII3gIwXFNlnaX9E1glRGS//8Ph8X+ IoB9vdzS3miDpqPOJUGo0BbM7Ovj3MRzoJlmKako/mjJUZ4lh4LwHvAN7lunAcEZi2RN 5HZoHC397doQCG+tJRIhhR5Iia5d65v2PrtokoBBZVsQ84T5U+q1TEjJwrFa3qnzxpud nYGaKXl12/E0K++iBcjpn3U5Y+hcDxhIcMO05RchwTx+YadZO2X0dREeCk1S3IKFLhvD 8hkA== X-Gm-Message-State: AGRZ1gIio+lpAOxdBICACTVwPZ2Bm3XFmIPYo6fyVKCY/bG6s/wGN6vq Y+4AnHG0Qw9d9EECucv/7M8nqA== X-Google-Smtp-Source: AJdET5cclpNnyXEqMSatox1gWLSbjRGb1T9OPXc7z99xQXBj7Ut1E5SYAleD39g5Jh1OOvvEMcMjPw== X-Received: by 2002:a0d:ed84:: with SMTP id w126-v6mr6579320ywe.25.1541863476631; Sat, 10 Nov 2018 07:24:36 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 2002:a25:41cc:: with SMTP id o195-v6ls1746667yba.2.gmail; Sat, 10 Nov 2018 07:24:35 -0800 (PST) X-Received: by 2002:a5b:705:: with SMTP id g5-v6mr140357ybq.5.1541863475075; Sat, 10 Nov 2018 07:24:35 -0800 (PST) In-Reply-To: X-Original-Sender: MihailNajdenov@gmail.com Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Spam-Checked-In-Group: std-proposals@isocpp.org X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:40937 Archived-At: ------=_Part_1351_153098415.1541863474451 Content-Type: multipart/alternative; boundary="----=_Part_1352_1992381970.1541863474452" ------=_Part_1352_1992381970.1541863474452 Content-Type: text/plain; charset="UTF-8" On Friday, November 9, 2018 at 6:50:59 PM UTC+2, Brian Bi wrote: > > > > On Fri, Nov 9, 2018 at 3:19 AM > wrote: > >> There are multiple problems with '\n' >> >> First - it is ultimately C ("way") >> > This mailing list is about C++, not Java, Rust, Swift, etc. > This is not an argument. > There is some sort of miscommunication. The fact there no C++ way to insert a new line (only a UNIX special character way) is what I state an issue, considering the rest of the API > > Second, when we introduce simple output to beginners, for which cout is >> actually good because of overloading, >> when using '\n' we have to introduce additional topics >> - the fact a char can be more the one, well, character >> - special magic characters >> We also create asymmetry b/w what is used to start the output std::cout >> (an object), to modify it (hex) and what is used to end it ("magic"). >> > > What do you mean, "what is used to end it"? A semicolon? > std::cout //< start << 12.f << ' ' << std::hex //< modify << 255 << '\n'; //< finish (magic) Note that printf (and other languages) already use special characters to modify the output, so having an '\n' is not abrupt. But C++ streams are different, having to spell out a special character is odd and unintuitive for a beginner and a design deficiency in general. > >> >> This screams some design flaw - we should be able to insert a new lines >> the same way we modify the stream! >> > Yes, the way to do that is with '\n'. > > >> >> On its own std::endl has the flaw that it does not obey the "do one >> thing" rule. >> Once we deprecate it, this will shut down all the naive tutorials/courses >> still teaching it as the default! >> >> >> As for std::newline, we have options - >> >> std::nl //< even a beginner can "read" it >> std::newl //< orthogonal to endl >> std::br //< why not at this point! >> std::brl >> std::bl >> >> Geeks can still use `\n`, but a beginner (and a teacher) will have a >> simple, *correct, *go-to option that models the syntax already >> introduced (std::cout)! >> >> >> On Friday, November 9, 2018 at 8:22:26 AM UTC+2, PeterSommerlad wrote: >>> >>> So the better way is do better teaching. I show my students that they >>> should not use endl, except when they need it. >>> >>> Sent from Peter Sommerlad's iPad >>> +41 79 432 23 32 >>> >>> On 8 Nov 2018, at 23:43, Hyman Rosen wrote: >>> >>> On Thu, Nov 8, 2018 at 5:08 PM Brian Bi wrote: >>> >>>> I think the reason why novices use std::endl is that they're under the >>>> impression (no doubt perpetuated by incompetent educators) that std::endl >>>> is portable whereas '\n' isn't. >>>> >>> >>> I think novices use std::endl because that's how C++ formatted I/O >>> was presented for ages. I have the feeling, completely unsupported >>> by evidence, that the iostreams designers thought manipulators were >>> really keen, and wanted to have one that would always get used. >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "ISO C++ Standard - Future Proposals" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to std-proposal...@isocpp.org. >>> To post to this group, send email to std-pr...@isocpp.org. >>> To view this discussion on the web visit >>> https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxEDRbuJ8dqAtsX5A%40mail.gmail.com >>> >>> . >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "ISO C++ Standard - Future Proposals" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to std-proposal...@isocpp.org . >> To post to this group, send email to std-pr...@isocpp.org . >> To view this discussion on the web visit >> https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/b49f4c85-816b-4b35-851d-407061a8ef9f%40isocpp.org >> >> . >> > > > -- > *Brian Bi* > -- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/7da1f33f-c2c1-482f-8fc2-c23a9767a5ec%40isocpp.org. ------=_Part_1352_1992381970.1541863474452 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Friday, November 9, 2018 at 6:50:59 PM UTC+2, B= rian Bi wrote:


On Fri, Nov 9, 2018 at= 3:19 AM <mihailn...@gmail.com> wrote:
There are multiple problems with '\n'
First - it is ultimately C ("way")
This mailing list is about C++, not Java, Rust, Swift, etc.<= /div>
This is not an argument.

<= /div>
There is some sort of miscommunication.=C2=A0
The fact = there no C++ way to insert a new line (only a UNIX special character way) i= s what I state an issue,=C2=A0
considering the rest of the API=C2= =A0
=C2=A0

Second, when we introduce simple output to= beginners, for which cout is actually good because of overloading,
when using '\n' we have to introduce additional topics=C2=A0
=
=C2=A0- the fact a char can be more the one, well, character
=C2=A0- special magic characters
We also create asymmetry b/w wh= at is used to start the output std::cout (an object), to modify it (hex) an= d what is used to end it ("magic").
=C2=A0
What do you m= ean, "what is used to end it"? A semicolon?

std= ::cout=C2=A0 =C2=A0 =C2=A0//< start=C2=A0
=C2=A0 << 12.f=C2=A0
=C2=A0 << ' '=C2=A0
=C2=A0 << std::hex //&l= t; modify
=C2=A0 <= ;< 255
=C2=A0 <= ;< '\n';=C2=A0 =C2=A0 //< finish (magic)=C2=A0

Note that printf (and other languages) already use = special characters to modify the output, so having an '\n' is not a= brupt.

But C++ streams are different, having to sp= ell out a special character is odd and unintuitive for a beginner and a des= ign deficiency in general.=C2=A0=C2=A0


<= blockquote class=3D"gmail_quote" style=3D"margin: 0;margin-left: 0.8ex;bord= er-left: 1px #ccc solid;padding-left: 1ex;">
=C2=A0

This screams some design flaw - we should be ab= le to insert a new lines the same way we modify the stream!
Yes, the way to do that is with '\n'.
=C2=A0

=
On its own std::endl has the flaw that it does not obey the &quo= t;do one thing" rule.
Once we deprecate it, this will shut d= own all the naive tutorials/courses still teaching it as the default!=C2=A0=


As for std::newline, we have optio= ns -=C2=A0

s= td::nl //< even a beginner can "read" it
std::newl //< orthogonal to endl
std::br //< why not at= this point!
std::br= l
std::bl

Geeks can still use `\n`, but a beginner (and a teach= er) will have a simple, correct,=C2=A0go-to option that models the s= yntax already introduced (std::cout)!


On Friday, November= 9, 2018 at 8:22:26 AM UTC+2, PeterSommerlad wrote:
So the better way is do better teaching. = I show my students that they should not use endl, except when they need it.=

Sent from Peter Sommerlad's=C2=A0iPad
+41 79 432 23 32

On 8= Nov 2018, at 23:43, Hyman Rosen <hyman...@gmail.com= > wrote:

On Thu, Nov 8, 20= 18 at 5:08 PM Brian Bi <bbi...@gmail.com> wro= te:
I think the reason why novices use std::endl is that they'= ;re under the impression (no doubt perpetuated by incompetent educators) th= at std::endl is portable whereas '\n' isn't.
<= /blockquote>

I think novices use std::endl because that's how C= ++ formatted I/O
was presented for ages.=C2=A0 I have the feeling, compl= etely unsupported
by evidence, that the iostreams designers thought mani= pulators were
really keen, and wanted to have one that would always get = used.

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposal...@isocpp.org.
To post to this group, send email to std-pr...@isocpp.o= rg.
To view this discussion on the web visit https://groups.google.com/a/isocpp.org= /d/msgid/std-proposals/CAHSYqdYYZjeHHbRZ5bcHLYVsWfspwCeQ8oxE= DRbuJ8dqAtsX5A%40mail.gmail.com.

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposal...@isocpp.org.
To post to this group, send email to std-pr...@isocpp.org.
To view this discussion on the web visit https://groups.google.com= /a/isocpp.org/d/msgid/std-proposals/b49f4c85-816b-4b35-851d-= 407061a8ef9f%40isocpp.org.


--
Brian Bi=

--
You received this message because you are subscribed to the Google Groups &= quot;ISO C++ Standard - Future Proposals" group.
To unsubscribe from this group and stop receiving emails from it, send an e= mail to std-proposa= ls+unsubscribe@isocpp.org.
To post to this group, send email to std-proposals@isocpp.org.
To view this discussion on the web visit https://groups.google.= com/a/isocpp.org/d/msgid/std-proposals/7da1f33f-c2c1-482f-8fc2-c23a9767a5ec= %40isocpp.org.
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